Following many urological procedures, it is often necessary to regularly irrigate the urinary bladder to flush out blood clots, stones, pieces of tissue and the like. This is generally achieved by introducing a sterile liquid into the bladder, withdrawing the liquid containing the material to be removed, and repeating the process a number of times.
At present, the most commonly used device for bladder irrigation is the Ellik evacuator. The Ellik evacuator comprises a pair of integrally formed chambers disposed in vertical alignment and having a restricted, central passageway in open communication between the two chambers. The upper chamber is provided with two ports, one of which is adapted for connection to a manually compressible bulb, the other of which is adapted for connection to a resectoscope for insertion into the urinary bladder.
In use the Ellik evacuator is completely filled with a sterile irrigation fluid and the resectoscope catheter passed into the bladder. Upon compression of the bulb, the sterile liquid is forced into the bladder, and is withdrawn following release of the bulb. Tissue and other particulate matter in the withdrawn fluid, which have a specific gravity greater than that of the sterile liquid, will tend to settle through the opening between the two chambers into the lower chamber. However, compression of the bulb produces eddy currents in the fluid in the upper chamber. These eddy currents tend to cause a portion of the particulate matter to remain in suspension, with the result, that tissue and other particulate matter are reinjected into the bladder each time the bulb is compressed after the initial compression. This is particulary is particularly the case when small prostatic chips or frond-like segments of a papillary bladder tumor are present, as they tend to float in the upper chamber and do not settle into the lower chambers.
A number of other disadvantages are encountered in using the Ellik evacuator, including the difficulty encountered in filling the Ellik evacuator and removing all the trapped air. This is particularly tedious as the filling procedure has to be repeated a number of times depending on the bulk of tissue that is resected. Each time the Ellik evacuator is emptied and refilled, the tissue that has been collected is separated from the Ellik evacuator. This requires the additional step of collecting the discarded tissue from drapes or irrigant basin later.
The Ellik evacuator is also an inefficient system, especially if a large bulk of tissue is resected. The large bulk of tissue tends to fill the lower chamber, thereby increasing the rate of flushing chips back into the bladder. The alternative is to empty and refill the Ellik evacuator more frequently. Even a partially filled lower chamber can result in this difficulty because irrigation vortices are created. The vortices tend to lift those chips that have already settled into the lower chamber back into the upper chamber, from where they are easily flushed back into the bladder.
The Ellik evacuator also creates a feeling of insecurity, since the surgeon must suspect that some chips remain in the bladder. The only way to correct this problem is to continue to empty and refill the Ellik evacuator until it remains clear through the final irrigation.
U.S. Pat. No. 3,892,226 is directed toward a urological irrigation-evacuator which seeks to overcome some of the difficulties encountered with the Ellik evacuator. This device comprises a fluid receptive manually compressible bulb and a specimen collecting receptacle. In fluid connection with the collecting receptacle is a first conduit means which is adapted to be connected to a resectoscope. In parallel array to the first conduit means is a second conduit means which is in fluid contact with the compressible bulb. There are two one-way valve means which provide fluid contact between the first and second conduit means; one providing contact between the upper portions of the conduits, and the other providing contact between the lower portions of the conduits.
In operation, the device of U.S. Pat. No. 3,892,226 is filled with sterile liquid and connected to a resectoscope which is passed into the urinary bladder. Upon compression of the bulb, liquid is forced from the second conduit, through the one-way valve connecting the upper portions of the conduits, into the first conduit, and from there into the bladder via the resectoscope. Release of the bulb generates negative pressure resulting in withdrawal of the liquid from the bladder into the first conduit means. Tissue and other particulate particles in the fluid withdrawn from the bladder, which have a specific gravity greater than that of the liquid, tend to settle or gravitate toward the specimen collecting receptacle. At the same time liquid is drawn from the first conduit means into the second conduit means through the one-way valve connecting the lower portion of the conduits. The tissue and other particulate matter is prevented from entering the second conduit means by means of a sieve which is positioned over the one-way valve connecting the lower portions of the conduit means.
Following the withdrawal of the fluid from the urinary bladder, the bulb is compressed once again and the process repeated.
While the device disclosed in U.S. Pat. No. 3,892,226 overcomes some of the problems encountered with the Ellik evacuator, it still relies on sedimentation of t he particulate matter drawn into the first conduit. Compression of the bulb will result in eddy currents being produced in the first conduit tending to cause the particulate matter to remain in suspension causing their reintroduction into the bladder.